A natural landscape acts like a sponge, allowing rainfall to soak into the ground. This replenishes the groundwater, which keeps creeks flowing after rains end.
Paved surfaces prevent percolation and send runoff to creeks more quickly and in greater quantity, causing increased creek erosion and flooding. As rain water runs across roads, rooftops, driveways and parking areas in your neighborhood, it picks up pollutants such as motor oils, metals, pesticides and litter. Stormwater pollutants like these come from our everyday activities. The polluted water from our neighborhoods enters the storm drains and flows to local creeks and the San Francisco Bay, without any cleaning or filtering to remove pollutants.
Help rainfall soak into the ground to reduce these problems You can these watershed-friendly or “Low Impact Development” (LID) techniques to absorb rainwater in your yard and break the chain of impervious surfaces – from roof, to driveway, to street, to storm drain, and to creek. LID site designs mimic the natural landscape, so rainwater can filter through vegetation and/or soil, to reduce the amount of water entering the storm drain.